Replace bhyve's minimal RTC emulation with a fully featured one in vmm.ko.

The new RTC emulation supports all interrupt modes: periodic, update ended
and alarm. It is also capable of maintaining the date/time and NVRAM contents
across virtual machine reset. Also, the date/time fields can now be modified
by the guest.

Since bhyve now emulates both the PIT and the RTC there is no need for
"Legacy Replacement Routing" in the HPET so get rid of it.

The RTC device state can be inspected via bhyvectl as follows:
bhyvectl --vm=vm --get-rtc-time
bhyvectl --vm=vm --set-rtc-time=<unix_time_secs>
bhyvectl --vm=vm --rtc-nvram-offset=<offset> --get-rtc-nvram
bhyvectl --vm=vm --rtc-nvram-offset=<offset> --set-rtc-nvram=<value>

Reviewed by:	tychon
Discussed with:	grehan
Differential Revision:	https://reviews.freebsd.org/D1385
MFC after:	2 weeks

2 files changed, 24 insertions, 0 deletions

diff --git a/sys/amd64/include/vmm.h b/sys/amd64/include/vmm.h
index 8a8c3f4..eef5efa 100644
--- a/sys/amd64/include/vmm.h
+++ b/sys/amd64/include/vmm.h
@@ -286,6 +286,7 @@ int vm_unassign_pptdev(struct vm *vm, int bus, int slot, int func);
 struct vatpic *vm_atpic(struct vm *vm);
 struct vatpit *vm_atpit(struct vm *vm);
 struct vpmtmr *vm_pmtmr(struct vm *vm);
+struct vrtc *vm_rtc(struct vm *vm);
 
 /*
  * Inject exception 'vme' into the guest vcpu. This function returns 0 on
diff --git a/sys/amd64/include/vmm_dev.h b/sys/amd64/include/vmm_dev.h
index e4d839e..3097386 100644
--- a/sys/amd64/include/vmm_dev.h
+++ b/sys/amd64/include/vmm_dev.h
@@ -195,6 +195,15 @@ struct vm_intinfo {
 	uint64_t	info2;
 };
 
+struct vm_rtc_time {
+	time_t		secs;
+};
+
+struct vm_rtc_data {
+	int		offset;
+	uint8_t		value;
+};
+
 enum {
 	/* general routines */
 	IOCNUM_ABIVERS = 0,
@@ -254,6 +263,12 @@ enum {
 	/* vm_cpuset */
 	IOCNUM_ACTIVATE_CPU = 90,
 	IOCNUM_GET_CPUSET = 91,
+
+	/* RTC */
+	IOCNUM_RTC_READ = 100,
+	IOCNUM_RTC_WRITE = 101,
+	IOCNUM_RTC_SETTIME = 102,
+	IOCNUM_RTC_GETTIME = 103,
 };
 
 #define	VM_RUN		\
@@ -336,4 +351,12 @@ enum {
 	_IOW('v', IOCNUM_SET_INTINFO, struct vm_intinfo)
 #define	VM_GET_INTINFO	\
 	_IOWR('v', IOCNUM_GET_INTINFO, struct vm_intinfo)
+#define VM_RTC_WRITE \
+	_IOW('v', IOCNUM_RTC_WRITE, struct vm_rtc_data)
+#define VM_RTC_READ \
+	_IOWR('v', IOCNUM_RTC_READ, struct vm_rtc_data)
+#define VM_RTC_SETTIME	\
+	_IOW('v', IOCNUM_RTC_SETTIME, struct vm_rtc_time)
+#define VM_RTC_GETTIME	\
+	_IOR('v', IOCNUM_RTC_GETTIME, struct vm_rtc_time)
 #endif